Can you answer this one? It is challenging

[Sam]

Well, after I finished tuning my rws 34 in 0.177 (replaced the spring and the piston seal plus lube) and after I was able to assemble it back, I tried to shoot it.  I was using JSB exact 8.4 gr and the rifle smoked with every pellet, I cleaned the barrel but the smoke did not stop (thick white smoke).  then I switched to CPHP, RWS super dome, and RWS meisterkuglen pellets and there is no smoke at all.  I went back to the JSB and the rifle smoked again, not let up in the smoke.  I thought there was something with the JSB pellets so I broght my R-9 and shot the JSB and there was NO smoke.  Back to my RWS, it smoked!  What is going on here?

[Big_Bill]

Hey Sam,

You have combustion happening with the smoke, and I would guess that the other pellets have a better seal allowing the better total combustion in the barrel.

I don't know what lube you used around your seal,but if the heavy combustion continues, you'll burn your seal.

Bill

[Orin]

Maybe because JSB pellets have smaller heads and very thin skirts, adequate back pressure is not being provided to the piston to prevent dieseling?  I'm sure it will go away soon, but that IS strange.

- Orin

[geewhiz380]

Like bill said the smoke has to stop otherwise seals will be damage.remove some lube if u gave it to much and dont use the jsb exact some pellets release more residue than others .most likely its the lube u used or the amount u put ...jorge

[Sam]

I used generous amount of the moly lube at the seal and the piston seal.  There is no way I can dis-assemble the rifle at this stage and remove some of the lube after all trouble that I have to go through in the assembling process.  I will be using different pellets for now, I just hope it will not damage the seal.  I have a feeling that this rifle, which is new, will not be in my collection in the near future.  I will keep you updated...Sam.

[daved]

Hate to say it, but "generous amounts" is probably the problem.  Sounds like some of it got ahead of the piston seal.  I'm a little confused by your statement, though.  You said "at the seal and the piston seal".  The piston seal I get, but what's the other seal you're referring to?  If it's the breech seal, that's at least part of the problem.  Clean it out, if so.  

My 34 doesn't like JSB's at all, especially Exacts.  It's favorite pellet at the moment is CPL's, followed closely by Crow Magnums.  If you have some on hand, you might try shooting some heavier pellets for awhile.  This can help in a dieseling situation like yours.  I assume you used a Macarri spring, if so, you won't hurt it with the heavy pellets.

Another thought, did you deburr the cocking slot, etc., before replacing the piston?  If the answer is no, you could easily have nicked the new piston seal on reassembly.  Give it time, the 34 is a great little rifle.  Once you get it sorted out, I think you'll be very happy with it.  Good luck.

Dave

[Sam]

Daved, yes I did confuse you what I meant to say is that I lubricated the seal and the piston with moly lube.  Yes, I did use Macarri spring and I have some CP 10.5 gr to use.  I never had problem with the JSB exact before the tune, in fact, I was shooting a bulleye at 20 yards open sight with these JSB exact pellets and my RWS seemed to like them a lot.  Actulay I did nick the seal a little on the side.  I was very happy with my RWS, never had problem with it...Thanks.

[howie1a]

When you lube a air rifle you need to make sure you don't get any lube ahead of the piston seal or you will have lube in the compression chamber and cause smoke you need to lube the piston behind the seal incase their is any metal touching the chamber and no lube in the chamber when you put the piston into the chamber after when putting the spring into the chamber it's ok to lube the spring mainly the spring ends.so when the spring rotates as it compresses and unwindes it has some lube. I think you must have got some lube in front of the seal it will work out after a while if you don't want to take down the rifle again. Howie

[Sam]

I guess I have lubed everything that I'm not suppose to.  My 1st tune.  I just hope I did not kill my RWS.

[howie1a]

It's not a big deal just take it apart again wipe all the lube out of the chamber and off the front and sides of the seal and put it together it should be fine, The lube on the spring and the side of the piston behind the seal is enought to lube the seal as the gun is cocked the seal wipes the chamber down and a very small amt of lube work's it's way forward and lubes the seal edges this is enough for the air rifle. We have all been their as we learned to work on air guns. Howie

[Gene_SC]

When lubing a springer, a little bit goes a lonnnnnnnng ways...

[michael90t]

doubt that you "killed" the gun LOL but hopefully the seal wont burn up and or you nicked it to bad to seal properly... worst case... you have to buy another seal and this time build a spring compressor to do the job right... its a learning experience

two words that DON'T go together when working on a springer is generously and lubed LOL even on the spring ends you don't want to much as it can and will fling off and can work its way into the chamber causing dieseling and detonation

[Sam]

So the question is, where do you apply the moly lube?  I'm asking this becuase when I looked at Tom Gaylord's tune of the R-1, I noticed that many parts were coated with this lube including the seal itself.

[michael90t]

for the moly you really just want to "shine" the seal with it.. best way I can think of to describe it.... you don't want it dry but you don't want globs of it on there either... and you don't want to put any on the face of it at all... then a very light coat right behind the seal on the piston itself once again you don't want it dry but no globs either and then the same thing on the back of the piston where it rides in the tube..

if your using heavy tar then you will want to put some on both ends of the spring for a couple inches on the outside of it and then some moly on the top hat if it has one and a good coat on the springguide... if your just using moly the replace the tar with moly and your good but you use even less on the outside of the spring....

Remember alittle goes a long way and to much will sling off and work its way into the compression cylinder causing problems...

if you end up having to take it back apart you WILL want to make sure you swab out the action tube really well to remove any extra lube that will be inside it before you relube and reassemble

[tjk]

Sam, if your rifle is smoking alot, but it isn't going "BANG", then you are dieselling heavily. If it does go "BANG" when fired, which is detonation, stop at once, build a spring comp and break it down as the others have mentionned. If sounds to me like your rifle is running a little "rich". As long as it's just dieseling, then I would shoot continue in it for a while and cycle the excess lubes out of it. Like a new rifle,....just keep shooting it. The worst you will do is dirty up the barrel more frequently.  I've had the same thing happen with my 34 and for a while I only used thick skirted pellets like the RWS super-domes and pellets on the heavy side of the weight spectrum like cro mags (my 34's a .22).
I really don't think your going to damage the seal with heavy dieselling because your not generating enough 'energy/heat' to cause any burning etc. If it does go "bang" real loud, then this is where seal damage can occur from detonation (high heat actually burning the lubes and seal). That's my two-cents. Good Luck, tjk